This article discusses the findings of an exploratory study into the nature and influencing factors of front-line employee deviant behaviour in service encounters in two hospitality industries. A dual perspective approach was used that involved employees and customer perceptions. Interviews were conducted with service managers and front-line employees from hospitality and adventure tourism organizations in New Zealand. Data from customers was obtained from written scenarios and customer feedback. Based on the outcomes of this study and related literature, a definition of service deviance and a typology to describe four different types of deviant behaviour are proposed. The findings of the study also indicate that the customer's attitude and behaviour is a key factor that influences front-line employees to engage in acts of deviance. The implications of the findings for service organizations and future research directions are discussed.